blob: cd41d965f700b4e13912525482fb4a24fa7c1e35
1 | /* |
2 | * ALSA input and output |
3 | * Copyright (c) 2007 Luca Abeni ( lucabe72 email it ) |
4 | * Copyright (c) 2007 Benoit Fouet ( benoit fouet free fr ) |
5 | * |
6 | * This file is part of FFmpeg. |
7 | * |
8 | * FFmpeg is free software; you can redistribute it and/or |
9 | * modify it under the terms of the GNU Lesser General Public |
10 | * License as published by the Free Software Foundation; either |
11 | * version 2.1 of the License, or (at your option) any later version. |
12 | * |
13 | * FFmpeg is distributed in the hope that it will be useful, |
14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
16 | * Lesser General Public License for more details. |
17 | * |
18 | * You should have received a copy of the GNU Lesser General Public |
19 | * License along with FFmpeg; if not, write to the Free Software |
20 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
21 | */ |
22 | |
23 | /** |
24 | * @file |
25 | * ALSA input and output: definitions and structures |
26 | * @author Luca Abeni ( lucabe72 email it ) |
27 | * @author Benoit Fouet ( benoit fouet free fr ) |
28 | */ |
29 | |
30 | #ifndef AVDEVICE_ALSA_H |
31 | #define AVDEVICE_ALSA_H |
32 | |
33 | #include <alsa/asoundlib.h> |
34 | #include "config.h" |
35 | #include "libavutil/log.h" |
36 | #include "timefilter.h" |
37 | #include "avdevice.h" |
38 | |
39 | /* XXX: we make the assumption that the soundcard accepts this format */ |
40 | /* XXX: find better solution with "preinit" method, needed also in |
41 | other formats */ |
42 | #define DEFAULT_CODEC_ID AV_NE(AV_CODEC_ID_PCM_S16BE, AV_CODEC_ID_PCM_S16LE) |
43 | |
44 | typedef void (*ff_reorder_func)(const void *, void *, int); |
45 | |
46 | #define ALSA_BUFFER_SIZE_MAX 65536 |
47 | |
48 | typedef struct AlsaData { |
49 | AVClass *class; |
50 | snd_pcm_t *h; |
51 | int frame_size; ///< bytes per sample * channels |
52 | int period_size; ///< preferred size for reads and writes, in frames |
53 | int sample_rate; ///< sample rate set by user |
54 | int channels; ///< number of channels set by user |
55 | int last_period; |
56 | TimeFilter *timefilter; |
57 | void (*reorder_func)(const void *, void *, int); |
58 | void *reorder_buf; |
59 | int reorder_buf_size; ///< in frames |
60 | int64_t timestamp; ///< current timestamp, without latency applied. |
61 | } AlsaData; |
62 | |
63 | /** |
64 | * Open an ALSA PCM. |
65 | * |
66 | * @param s media file handle |
67 | * @param mode either SND_PCM_STREAM_CAPTURE or SND_PCM_STREAM_PLAYBACK |
68 | * @param sample_rate in: requested sample rate; |
69 | * out: actually selected sample rate |
70 | * @param channels number of channels |
71 | * @param codec_id in: requested AVCodecID or AV_CODEC_ID_NONE; |
72 | * out: actually selected AVCodecID, changed only if |
73 | * AV_CODEC_ID_NONE was requested |
74 | * |
75 | * @return 0 if OK, AVERROR_xxx on error |
76 | */ |
77 | av_warn_unused_result |
78 | int ff_alsa_open(AVFormatContext *s, snd_pcm_stream_t mode, |
79 | unsigned int *sample_rate, |
80 | int channels, enum AVCodecID *codec_id); |
81 | |
82 | /** |
83 | * Close the ALSA PCM. |
84 | * |
85 | * @param s1 media file handle |
86 | * |
87 | * @return 0 |
88 | */ |
89 | int ff_alsa_close(AVFormatContext *s1); |
90 | |
91 | /** |
92 | * Try to recover from ALSA buffer underrun. |
93 | * |
94 | * @param s1 media file handle |
95 | * @param err error code reported by the previous ALSA call |
96 | * |
97 | * @return 0 if OK, AVERROR_xxx on error |
98 | */ |
99 | av_warn_unused_result |
100 | int ff_alsa_xrun_recover(AVFormatContext *s1, int err); |
101 | |
102 | av_warn_unused_result |
103 | int ff_alsa_extend_reorder_buf(AlsaData *s, int size); |
104 | |
105 | av_warn_unused_result |
106 | int ff_alsa_get_device_list(AVDeviceInfoList *device_list, snd_pcm_stream_t stream_type); |
107 | |
108 | #endif /* AVDEVICE_ALSA_H */ |
109 |